The huntclub fells like it's an under utilized system. Inorder to flesh it out I think cosmetics could be used as rewards.
The basic idea is that your dedication to a weapon is shown. My first idea was with a set ammout of harvest a new cosmetic/cosmetic preset I'd unlocked. This should be easy enough as the game already tracks weapon specific harvests for the trophy lodge. My revised idea is almost the same however it would utilize weapon score rather than just the harvest number. I prefer the weapon score approach because it puts emphasis on using an appropriate weapon and making good shots. To my knowledge the game doesn't track weapon score tied specifically for a given weapon but just in general per weapon class. I am unaware of the max weapon score per harvest so I'll use 50 for my example.
Ex. First idea : get 100 harvests with the 45-70 leaver action.
Ex. Revised idea : get 5000 weapon score with the 45-70 leaver action.
The specifics on the amount of harvests and weapon score per cosmetic/cosmetic preset would have to be determined by EW. I was thinking 100/500/1000 harvest or equivalent weapon score.
The idea of a cosmetic preset stems from before the cosmetic system was added. We can think of this as an entire new reskin.
Ex. 7mm regent and 7mm empress
Rather than selecting individual cosmetic components you can select entire reskins. The unlocks from the huntclub would be entire reskins we could drop on our weapons in the cosmetic menu.
Another idea would bet to add names to the cosmetic based on the firearm heritage. Leaver guns get cowboy themed cosmetic names. The .303 gets named after British WWI soldier nicknames. And so on for the other weapons.
Personally I am a fan of more traditional firearms so my demonstration pictures will reflect that.